Profile edge and rabbet grinding machine



Dec. 8, 1964 K. HEESEMANN 3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July so, 1962 6Sheets-Sheet 1 fm/errtar: Karl Hese mann nrrvs.

Dec. 8, 1964 K. HEES EMANN 3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July so, 1962 eSheets-Sheet 2 .[m emar? Karl Heesemcm n ggfpm Dec. 8, 1964 K. HEESEMANN3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July 30, 1962 6Sheets-Sheet 5 m emon' Karl He esemarm yuaj-m ATTYJ.

Dec. 8, 1964 K. HEESEMANN PROFILE EDGE AND RABBET GRINDING MACHINE FiledJuly 30, 1962 6 Sheets-Sheet 4 K Nu R an mw mm mm mm on R mm M mm mm mmmm mm mm mm mm vm [we/#021 Karl Heesemann Dec. 8, 1964 K. HEESEMANN3,159,949

PROFILE EDGE AND RABBET GRINDING MACHINE Filed July 30, 1962 6Sheets-Sheet 5 jm/emon' Karl Heesemann Ar-ryx Dec. 8, 1964 K. HEESEMANNPROFILE EDGE AND RABBET GRINDING MACHINE Filed July so, 1962 6Sheets-Sheet 6 mm mm mm mm mm mm Wm an 5 mm m m A ee Wa d e H UnitedStates Pate 3,159,949 raornr. anon AND Planner GRZNDEJG Manama KarlHeesemann, 5 Friedenstrasse, iiehme uher. Bad @eynhausen, Germany Filed.luly Sit, i962, Ser. No. 213,386 laims priority, application Germany,Get. 28, 1961,

H 43fi93 15 Claims. (Cl. 51-138) 7 This invention relates to abandgrinding machine for profile, edge and rabbet grinding, in which apreferably large-area workpiece is fed on a work table along an abrasiveband preferably parallel to the direction of movement thereof.

In the machines of this type hitherto known the work table is mounted onthe frame. of the machine so that it is adjustable in height,horizontally and at an angle to the abrasive hand. If it is desired togrind, by such machines, profiles or other shapes on chiefly large-areaworkpieces, such as for example upper rims, bottom rims or plates, whichshapes form an acute angle to the bearing surface of the workpiece oreven extend parallel thereto, the work table must be displaced to acorresponding degree. Due to the feeding elements for the.

workpiece such an adjustment is, however, only possible to a limitedextent, with the result that such profiles cannot be ground on theabove-mentioned machines. The conventional machines are also open to theobjection that the working height changes continually owing to thenecessary adjustment of the work table.

One object of the invention is to overcome these objections.

According to the invention, a hand grinding machin for profile, edge andrabbet grinding comprises a frame, a work table mounted on said frame, aconveyor mounted in said table for feeding workpieces along said table,an axle extending parallel to the path of movement of the workpieces, atleast one endless circulating abrasive band, and driving, guiding andpressing-on devices for said abrasive band swingable together with saidabrasiv band about said axle. Y

The abrasive band with its driving, guiding and pressing-on device mayalso be shiftable in vertical and/or horizontal direction.

According to a preferred embodiment the pivot axle is constituted by acarrier axle which carries the abrasive hand with its driving, guidingand pressing-on devices, and carriages are provided in which saidcarrier axle is mounted and which are shiftable in height and/ orlaterally in relation to the frame.

The machine according to the inventionallows the abrasive band to beadjusted with its driving, guiding and pressing-on devices at an angleand possibly also in vertical and horizontal direction to such a degreethat it can always be brought into the necessary position in relation tothe workpiece moving on the work table serving as a workpiece guide.Thework table may be rigidly mounted on the main frame of the machine ormay be additionally adjustable in height. The feeding and guidingdevices for the workpiece are at the same time prefer ably so arrangedthat they form an aggregate with the Work table and consequently withthe main frame and are not influenced by the adjustmentof the grindingaggregate. A profile, edge andrabbet grinding machine,

particularly with the above-mentioned features of the invention,enablestwo opposite edges of a workpiece to be ground in an advantageousmanner'in a single passage of the workpiece.

' On the band grinding machines hitherto 'khbwh for such twosidedgrinding, it is only possible to grindtwo V opposite straight edges onsolid wood "pieces to a-premeans Fatented Dec.v 8, 1964 ice chines thenlack the adaptability to the workpiece which is necessary for suchgrinding work. 7

. Another object of the invention is "to improve the hitherto knownprofile, edge and/or rabbet grinding machine-s with endless circulatingabrasivebands, on which two opposite edges of a workpiece can be groundin a single passage of the workpiece.

To achieve this object, the band grinding machine according to theinvention is provided with two oppositely arranged endless circulatingabrasive bands which are adjustable to the'width of the workpiece to befed between said abrasive bands substantially parallel to the directionof movement thereof, the pressing-on device comprising pressure shoes orpieces which are arranged to press said abrasive bands against theworkpiece fed in a straight line, guides being provided in which saidpressure pieces are mounted, adjustable weights serving for regulatingthe grinding pressure and elbow levers connecting said weight with atleast one of said pressure pieces. I a

By this construction both opposite abrasive bands can automaticallyadjust themselves to the Width of the workpiece within certain limits,so that, according to the ad- 7 justment of the slidable counterweights,a uniformly strong pressure is exerted by the pressure shoes against theabrasive bands and consequently against the work piece. As a result, thepoints at which the abrasive bands engage adapt themselves exactly tothe shape of the workpiece and the chip removal takes place only inaccordance with the' grinding pressure which has been set. The shape ofthe surface of the edge of the workpiece is not changed but ground outuniformly everywhere. It is thus possible to grind workpieces, the edgesof which are covered with very thin veneers, for example about 0.6 mm.in thickness and even constructed as rabbets or profiles. p, i

By such an arrangement of the pressure shoes the tolerances which; occurwith every workpiece are automatically taken into consideration withoutrunning the risk of the thin veneers being ground through.

Inan expedient form of construction of the'ban'd grindmg machineaccording to the invention, besides this automatic adjustment of thegrinding pressure, these pressure shoes or pieces can be so controlledthat they two abutments are arranged in the path of travel of the FIG.1;p

. FIG. 3 is a cross section through the machine taken i on line 111-411of FIG. 1;. r

pas-sing workpiece, guides-are provided on which said abutments areshiftahle in parallel relationship in the direction of movement oftheworkpiece, and control devices couple said abutments with the pressureshoes or These abutments are preferably constructed as pieces.

contact rollers which project into the range of the end edges of theworkpiece and are moved thereby.

Two preferred embodiments of the invention will now be described by wayof example and with reference to the accompanying drawings, in which: 5

FIG. '1 is a rear view of a band grinding machine according to theinvention with abrasive b and removed; FIG. 2 is a top plan view of'themachine shown in 1 16.4 is a sideielevationof a workpiece with a tile ata'yery acute angle to the work table .as well as j of a profiled toolwith the abrasiveband' located between ;the workpiece andl the' toolandshown insection;

rection.

FIG. is a section through a modified band grinding machine taken on lineV-V of FIG. 6, the band grinding machine being provided with twoopposite pressure shoes or pieces for endless circulating abrasivebands;

FIG. 6 'is a top plan view of the machine shown in FIG. 5;

FIG. 7 is a diagrammatic view, on a larger scale, of two contact rollersarranged side byside and mutually displaced as abutments for acontrolling device, thehousing of the rollers being shown partly insection;

FIG. 7a is a section through the housing of one of the contact rollersshown in FIG. 7, with the contact roller inside elevation, and

FIG. 8 is a longitudinal s'ectionthrough a control valve for moving thepressure shoesor'pie'ces.

Referring to FIGS. 1 to 3, a Work table 2 is fixed on a stand orframe 1. A conveyor belt 3 is fitted in the work table '2 in such amanner that it can transport a workpiece 4. The conveyor belt 3 isdriven by a geared motor (not shown), the speed of which is'infinitelyvariable. To ensure that the workpiece 4 has a good hold on the conveyorbelt 3, .it is pressed against the conveyor belt by pressure rollers 5which are provided, for example, with a suitable rubber cover andresiliently mounted in vertical direction. An abutment rail 6 on -thework table 2 forms an accurate straight guide for the workpiece 4.

An abrasive band 7 runs over a pulley 9 driven by a motor '8' and apulley 11 which can be 'tensioned by a band tightener 10. The drivingand tightening aggregates for the abrasive band 7 are mounted on; acarrier axle 12 which is rotatable about its axis in horizontal supports13. The carrier axle 12 is turnable about its axis by means of a wormgear 15 with a band wheel 16. This worm gear 15 is self-locking sothatthe carrier axle 12 is fixed in any adjusted position. Thehorizontal supports 13 are adjustable in horizontal direction on guiderods 17 by meansof a spindle 18- connected with a hand wheel 19. Theguide'rods 17 are arranged in a vertical carriage 20 which is guided onvertical'iguides 21 fixed-in the frame 1. The vertical carriage 20-can.be adjusted in vertical direction by a spindle 22 provided with ahandwheel 23. v v

The pressure rollers 5 are arranged ona pressure beam 24 soas to beadjustable inheight and inhor'izontal di- The pressure beam 24=is-'fittedon horizontal arms 25 which are adjustable in height jointlyor indi: vidually on two posts 26. These posts 2 6 are rigidly connectedto the frame 1 'so' that the pressure elements 5, 24 and 25 form a unitwith the frame 1. t

If workpieces 4 are to be ground on the machine, the vertical support 20and the horizontal carriages 13 are so adjusted and. the carrier. axle12 is turned about its axisthrough such an angle that the undeformedabrasive band 7 runs parallel to the surface to be ground on theworkpiece 4 and about in the -middle thereof.

In FIG. 4 a difierent workpiece 27 is shown having a profile which formsa very acute angle with the work table 2. The abrasive band 7 isundeformed in the position shown and lies substantially parallel to thetangent of the profile shape. The abrasive band 7 is pressed against theprofile to be ground bymeans of a profiled tool 28. The abrasive band '7is thereby deformed to correspond to the profile shape to be ground. i

For grinding such parts the whole grinding vaggregate is therefore swungabout the'carrier axle 12 and adjusted in vertical: and horizontaldirection so that the abrasive hand assumes the correct position to theprofile tobe 7 ground.

The modified construction shown in FIGS. 5, 6, 7, 7a.

and 8 has the same fundamental construction. A work table 32 is fixed ona mainframe 31 and aconveyor belt.

33 -is built thereinfso that it canconvey a workpiece l 34 resting onit. The conveyor belt'33 is driven by'a geared motor (not shown), thespeed of which is infi easily adjustable in axial direction.

. nitely variable. To give the workpiece 34 a good hold onthe conveyorbelt 33, it is pressed against the conveyor belt 33 by pressure rollers35 which are provided, for example, with a suitable rubber cover andmounted so that they are resilient in vertical direction. An abutmentrail 36 forms an accurate straight guide for the workpiece 34.

An endless abrasive band 37 (FIG. 6) runs over a pulley 33 driven by amotor (not shown) and a pulley 49 adjustable by a belt tightening device39. The driving and tightening aggregates for the abrasive band arearranged on a carrier. axle 41. The carrier axle 41 is mounted inhorizontal carriages 42 so as to be turnable about its axis by means ofa worm gear 44 having a hand wheel 45. The worm gear 44' is self-lockingso that the carrier axle 41 is fixed in any adjusted position.

The horizontal carriages 42 are adjustable on guide rods 46 inhorizontal direction by means of a spindle 47' With a hand wheel 48 Theguide rods 46 arefixed in a vertical carriage 4? which is guided onvertical guides 50 fixed in the main frame 31. The vertical carriage 49is adjustable in vertical direction by means of a spindle 51 with a handwheel' 52. p

The pressure rollers 35 are arranged on a pressurebeam 53 so as tobeadjustable in height and in horizontal direction.

An endless abrasive band 54 runs over two pulleys 55 and a pulley 56,the pulley 56 being driven by amotor .57. The pulleys '55 and 56including the motor 57 are mounted in a carriage 58 which is adjustableon guides 59 in vertical direction by means of a spindlefitl; The guides59 are fixed on a horizontal carriage 61 whichisadjustable on guides 62'inhorizontal'direction by means of a spindle 63 with a hand wheel 64.The guides 62 are mounted at one end in the main frame 31"and at theother end in an auxiliany frame 75.

Two pressure shoes or pieces 65a and 6511, which press. theabrasivebands 37 and 54 from the inner sides thereof against the workpiece 34when grinding, are mounted by means of guide rods 66 on balls in guides67 so-that the guide rods 66 with the pressure pieces 65aand 65b are arerigidly connected to the guide rods 66. Two set screws 69 permit theadjustment of the range of movement of the pressure pieces 65a and 65bin relation to the abrasive bands 37 and 54 Holding arms 70 are arranged on the guides 67 and at their free ends elbow levers 72 aremounted so that they are rotatable about pivots 71 in the verticalplane. The elbow levers 72 are connected to the cross-members 68 bymeans of connect ing pieces 73. They carry counterweights 74 which areadjustable in longitudinal direction and exert moments of force aboutthe pivots 71. The gforcesresulting there from are transmitted by theguide rods 66'to the pressure pieces 65:: and 65b and there exert thegrinding pressure during the grinding operation. By adjusting thecounter- Weights 74 on the elbow levers 72, these forces or the grindingpressure can be adjusted within certain limits.

Two contact rollers" 76 and-77 are mounted so that they are elasticallyyieldable in housings 76a and 7741 by means of springs 76b and 77bandare slidable in the axial direction of the pressure beam 53 on guides78 and 79,

respectively. In FIG. 6 the contact rollers 76 and 77 are located sideby side; the working position in which the-contact rollers 76 and 77 aredisplaced in relation to each other is shown in FIG. 7. The contact-'rollers'76' and 77' (FIG. '7) operate limit switches 81 and -;-arrangedin the housings 76a and 77a, respectively, and

connected in series, so that they close a control circuit when bothcontactrollers-76 and 77 are in lowered position, that is,-.when noworkpiece is pass'ingunder the, con: tact rollers 76 and 77. By theclosing ofthe'circuit, coils 32a of two electromagnetic control-valves82 (FIG. 8) coordinated one to each of the pressure pieces 65::

and 65'!) or their guide rods 66 are energized, with the Cross-members68 result that slide valves 83 shift to the left in FIG. 8 and connectpassages 84 with outer chambers 85 and diaphragnls 86. Under the actionof compressed air the diaphragms 86 and push rods 87 connected therewithare moved towards the right, so that the cross-members as and the guiderods 66 lift the pressure pieces 65a and 65b oil the abrasive bands 37and 54 with the result that the grinding operation stops immediately.

When a fresh workpiece 4 approaches, the front contact roller '77 (FIG.7) is first raised. The contact of the limit switch 83 interrupts thecircuit and springs 86 move the slide valves 83 of the twoelectromagnetic control valves 52 towards the right. The compressed airpassages 84 are interrupted and the compressed air can escape from theouter chambers 85 through passages 29, so that the diaphragms 86 andconsequently the push rods 8'? move back into their initial positions.As a resuit, the cross-members e53 we again free and the pressure pieces65a and 6573 are pressed against the inner sides of the abrasive bandsunder the action of the counterweights 74, thereby pressing these bandsagainst the workpiece.

After the passage of the workpiece, the circuit is then again closedwhen the workpiece has run past the rear contact roller 76.

This two-contact-roller systern' and especially its arrangement enablesthe lag of all switching and control elements, the rate of deed and thedifferent lengths of feed paths necessary during the running in and outof the workpiece to be taken individually into consideration.

The control arrangement for the pressure shoes or pieces, equipped withcontact rollers as abutments, enables, particularly in combination withthe diaphragm control valves, the pressure pieces to be applied andremoved without jerk as the workpiece runs through. By shifting thecontact rollers parallel to the direction of travel of the workpiece,the moment when the pressure shoes or pieces move can be adjustedaccording to the rate of feed.

The movement of the pressure shoes or pieces when engaging and/ ordisengaging the abrasive bands can be controlled not only in the mannerdescribed but also in other ways, for example electrically,pneumatically, mechanically or by combinations of these means.

I claim:

1. A band grinding machine for profile, edge and rabbet grinding; saidmachine comprising a zfirame, a stationary work-supporting table mountedon said frame for supporting the piece to be worked, and at least onegrinding unit which is vertically and horizontally adjustable; saidgrinding unit comprising an endless abrasive band mounted forlongitudinal movement, driving means for driving said band inlongitudinal movement, means for guiding said band so that it isefiective Where needed, and a pressure device for forcing said band atleast at one point along its length against the piece being worked; aconveyor on said table for conveying pieces to be worked along saidtable past said points on said band; an axle disposed parallelto thepath of movement of the pieces to be worked, said grinding unit beingrotatably mounted as a Whole on said axle; and means for vertically andhorizontally adjusting the position of said aide with respect to saidtable.

2. A band grinding machine as claimed in claim 1, wherein the abrasiveband is so guided that the work- 7 pieces are fed in front thereof.

3.A band grinding machine as claimed in claim 1, wherein the abrasiveband is guided parallel to the feed direction of the workpieces.

4. A band grinding machine as claimed in claim 1, wherein said axle alsocomprises a carrier which carries the abrasive band with its driving,guiding and pressingon devices, and wherein supports are provided inwhich said axle is mounted and which are shiftable in height andlaterally in relation to the frame. l

5. A band grinding machine as claimed in claim 4, wherein the supportsare constructed as horizontal supports and guide rods serve for guidingsaid horizontal supports thereon and a spindle is provided for adjustingthe supports on said guide rods in horizontal direction.

6. A band grinding machine as claimed in claim 5,-

7. A band grinding machine as claimed in claim 6,

wherein vertical guides are fixed in the frame and the vertical carriageis shiftable on said vertical guides.

8. A band grinding machine as claimed in claim 4, wherein a self-lockingworm gear serves for adjusting and fixing the axle.

9. A band grinding machine as claimed in claim 1, wherein the conveyorcomprises an endless circulating conveyor belt, and further includingpressure rollers which are mounted vertically resilient on a pressurebeam and serve for pressingthe workpieces onto said conveyor belt.

10. A band grinding machine as claimed in claim 9, wherein posts areconnectedwith the {frame and horizontal arms are vertically shiftable onsaid posts and the pressure beam which carries the pressure rollers isarranged on said horizontal arms.

11'. A band grinding machine as claimed in claim 1, wherein twooppositely arranged endless circulating abrasive bands are providedwhich are adjustable to the width of the'workpiece to be fed betweensaid abrasive bands substantially parallel to the direction of movementthereof, wherein the pressing-on device comprises pressure shoes orpieces which are arranged to press said abrasive bands against theworkpiece fed in a straight line, wherein guides are provided in whichsaid pressure pieces are mounted, and wherein adjustable weights servefor regulating the grinding pressure and elbow levers connect saidweights with at least one of said pressure pieces.

12. A band grinding machine as claimed in claim 11,

wherein the pressure show or pieces are mounted on ball devices couplesaid abutments with the pressure shoes or pieces.

14. A band grinding machine as claimed in claim 13 wherein the abutmentsare constructed as contact rollers. 15. A band grinding machine asclaimed in claim 13,

wherein a magnet-controlled compressed air valve with diaphragm isprovided as each control device.

References Cited in the file of this patent UNITED STATES PATENTS2,456,217 'Rothrock Dec. .14, 1943 2,479,506 Payton Aug. 16, 19492,637,951 White May'l2, 1953 4 2,934,864

'Karbowski May 3, 1960

1. A BAND GRINDING MACHINE FOR PROFILE, EDGE AND RABBET GRINDING; SAIDMACHINE COMPRISING A FRAME, A STATIONARY WORK-SUPPORTING TABLE MOUNTEDON SAID FRAME FOR SUPPORTING THE PIECE TO BE WORKED, AND AT LEAST ONEGRINDING UNIT WHICH IS VERTICALLY AND HORIZONTALLY ADJUSTABLE; SAIDGRINDING UNIT COMPRISING AN ENDLESS ABRASIVE BAND MOUNTED FORLONGITUDINAL MOVEMENT, DRIVING MEANS FOR DRIVING SAID BAND INLONGITUDINAL MOVEMENT, MEANS FOR GUIDING SAID BAND SO THAT IT ISEFFECTIVE WHERE NEEDED, AND A PRESSURE DEVICE FOR FORCING SAID BAND ATLEAST AT ONE POINT ALONG ITS LENGTH AGAINST THE PIECE BEING WORKED; ACONVEYOR ON SAID TABLE FOR CONVEYING PIECES TO BE WORKED ALONG SAIDTABLE PAST SAID POINTS ON SAID BAND; AN AXLE DISPOSED PARALLEL TO THEPATH OF MOVEMENT OF THE PIECES TO BE WORKED, SAID GRINDING UNIT BEINGROTATABLY MOUNTED AS A WHOLE ON SAID AXLE; AND MEANS FOR VERTICALLY ANDHORIZONTALLY ADJUSTING THE POSITION OF SAID AXLE WITH RESPECT TO SAIDTABLE.